Every spell does not have a uniform casting time. Spells have one of three casting times: instant, short, and long. Instant and short are both used a lot. Long is currently used less frequently. We could subdivide casting times even more, but I think past a certain point, differentiating your choices becomes difficult.
Classes don't have the ability to do everything. Yes, any class has the ability to access any skill. A single character cannot excel at all skills. Any class can equip a great sword. If you want to rush a barbarian, a rogue, and a wizard into a mob swinging that sword, it's going to proceed differently for those three characters. PoE's fighters don't have class abilities to chuck fireballs. Rogues don't have class abilities to revive people. Paladins can't transform into animalistic forms.
If you do a comparison of class abilities, wizards have the most by a good margin (a little below 70). Druids and priests also have a lot of spells (about 45 each), but still fewer than wizards. Chanters and ciphers have the smallest list. I don't disagree that it would be cool to have more diverse options like polymorphs, spell doublers, sequencers, contingencies, time stop, etc. We designed a list of more diverse, complex, niche spells and most of them didn't wind up being implemented because of the enormous amount of time (and often specialized UI) that they demand. I would like to implement more of these in the future, but it wasn't realistic for core PoE because we were building all of the game systems from scratch.
No, the response is not surprising. Even so, I have always tried to be straightforward about why I make design decisions. None of these stated reasons have ever been because I have animosity toward caster classes (which would be pretty weird for any reason). Throughout the project I've tried to give casters the majority of the ability time, with wizards receiving the most even in that select group. I've tried to ensure that wizards have good access to personal protection magic, personal strengthening magic, and a mix of different offensive spells that do a variety of things: bounding from target to target, temporarily negating enemies' beneficial magic, sickening/terrifying anyone who comes near the wizard, swapping locations with an ally and hurting enemies caught between, temporarily stealing spells from enemy grimoires, etc. Is it enough? Clearly not for everyone, but this was honestly what we were able to do -- not because we decided to short-change spellcasters, but because even with 5 out of 11 classes (the casters) receiving about 3/4 of all abilities, we could only do so many special case scripts for them.