The three biggest (note, not only ) points

-It was patched over previous versions. You can’t play the non-reforged version anymore
-It removed features the previous version had. In particular networking
-It released with desync issues that would randomly drop players from the game. Wc3 doesn’t support rejoin so this basically killed maps depending on how severely they were affected (and note, it even affected normal maps. But custom maps suffered tremendously from this)

Like just given those three points: Why don’t you understand?

The fact you even say that custom games improved just makes me think you’re being dishonest for some reason…because it wasn’t some secret or even rare occurrence. 90% of custom maps were suffering it.

Yanked from the “other” site, section 3.e:

3e. State of the Game FAQ

WTii’s videos Warcraft 3 Reforged ONE YEAR Later… and TWO YEARS Later… as well as THREE YEARS Later… goes over some of these points and makes a number of observations and highlights.

• Why did Blizzard fail in the making Reforged? This article goes over some behind the scenes during the games development process.
• Custom Campaigns? Is finally back. Before now were and are still able play them in normal map form, if they were updated/transformed. Or make use of the Campaign Splitter that was made to split w3n files into w3m/w3x. The Quenching is a mod that can be used with some CCs. Or just use it with the normal campaign.
• Player Profiles? Yes, but it seems to mainly be ladder stats, W3C has more extensive ones.
• Cross-realm hosting? Yes its finally back again.
• Clans? Yes however in a glitchy state. And W3C has both custom made chat-rooms as well as clans.
• Ladder? Yes as of 1.33 its out but not working without issues. And W3C still going strong.
• Automated Tournaments? Not yet. Some communities have seasonal things going for both ladder and customs but nothing official yet. And should soon be a thing on W3C.
• Old BNet Chat System? No and on Europe realm chat do not auto-scroll either, is also in the way of the map description but toggle-able. And no kind of chat log with joins or leaves that we had before or timestamp on messages. W3C has made their chats in this “old school” spirit.
• Game Reconnection (GProxy)? No. In case of a player leaving disconnecting or crashing or desyncing that player is unable to rejoin. But it can be determined by looking at different things what the cause was, desyncs will have an UI glitch for the portrait, crashes might have a fatal/unknown error and DCs one can check the replay or logs.
• Competitive Customs & Ladders? Not really. However with Community made wc3stats and in the future FLO-host enables this in a number of forms with replay uploading.
• Hosting & BNet Commands? Yeah. But they are limited and do not work as they should or you’d wish. For example !ban is just a “long kick” preventing the banned player/user from rejoining that current lobby not all games you host, thus you can’t mange bans and need to black list them yourself. Commands found here. As well as a !stats and zoom via scroll.
• Campaign Overhaul to fit in with WoW? No. Five missions were remade and a most were reworked and to some degree, some “new” characters were introduced but not to the scale people wish or expected, for good or ill. However the Reforged version of the Campaigns difficulty among other things was updated more details here. As of patch 1.36.1 this is no longer the case as campaign was reverted back to its 1.32 state.
• Improved Cutscenes? Not like we saw during BlizzCon. This was aborted and as it looks now wont be a thing at all. What we had and have now is showcased in DailyWCRF’s Videos.
• Reforged(HD) Vs Classic (SD)? Well that is up to you. Reforged has a few things in the campaign that Classic don’t. Aside from that it would depend on preferences and the maps you want to play as some work better in either version or only in one. Most do use classic and some swap between them so by popular vote Classic(SD) would win as for reasons or factors well most of those are personal.
• Follow/Join or invite friends to lobbies? If you both are on the same gateway you can right click your friend and “Join Game”. However you have to restart the game to be able to do it again (keep in mind that Blizz-app server and Wc3 Gateway might not fully sync friend list and thus causing problems as well as not being online in Blizz-app). Invites seems to be fully-partly glitched and broken as of this moment(1.32.10).
• Are we able to select more than 12 units/buildings? No, unlikely to be added to the base game too. Small possibility to be added into the editor if at all.
• When will X be implemented? SoonTM. We do not know at this stage we used to have monthly patches and updates from blizzard but not atm. Some of this can be explained the Bloomberg article. Even though there is a team from Playside Studios out there working on the game again we still do not really have any ETA for things that is not mentioned in PTR or Patch notes.