bler144: 1-3 are true, though comparing to MM 6-8 isn't really a fair bar. Like saying every album your favorite band has done since their best album sucks by comparison.
Most of the complaints in #4 seem to be from people who never liked grid-based games in the first place.
MM 1-5 were quite big games as well. Actually word "Grand" is almost synonymous with MM worlds. Personally, I enjoy grid-based games, but MM X doesn't stand anywhere near close to any of MM I-V. It is short and tunnel'ish with no exploration skills, little variety and slow character progress. They also changed the names for all the classes, all the stats, there are barely any links to older MM worlds. For example, game doesn't have to be full 3D to feature character dolls like in MM VI-VIII (sure, MM IX didn't have that too but it was because game was rushed). This game might look good to those who never played grid-based games, but to those spoiled by MM I-V, this game has no place in MM series.
Optimization. MM games are synonymous with "optimized smooth engines", written on low level languages/Assembler. MM X? Those minimum requirements, you gotta be kidding... 512 RAM should be tops for this game. 4 GB+? 128 MB video card should be much more than sufficient. 512+? It isn't like the game runs at minimum specs very good either. It is spit in the face to games like MM VI, where there could be 100 monsters on screen, and game wouldn't slow down on PC with 32 MB RAM and few megs dedicated to video memory.
To sum those points, people got early unoptimized beta of game with 2 DRMs on top of it, which has nothing in common with game series it pretend to be part of. Imo, fits worst sequel definition.