I don't think reclaim is the problem. If you want to push bases at little or no risk you just build megalith or shielded mobile artillery. People that complain about mass gifts are those who look at poor late game decision making and then say its bad.
The number one reason T4 units die on push is because of 0 air control and getting bombed.
The number one reason T3 Spam dies on push is that they walk into shielded T4.
As it stands for a defensive base the only broken thing is the T2 artillery as that counters mobile artillery significantly. T2 artillery is already very expensive though.
I'd suggest decreasing T2 artillery fire rate, increasing its dmg so the dps is the same, and making it more accurate. That way T2 artillery is still useful, as a firebase unit and defense against fatty, but its not so broken as to render Mobile artillery useless.
Buffing t2 mobile shields would also greatly assisting sieges.
Also if you are truly spamming t3 armies then why is it so hard to send t1 engi at the back of it to pick up the reclaim?
What happens is people (especially high rated players) are complaining cause they'rein a team game where some random unknown 1000 builds monkeys and feeds 20k mass at a time. The reason they want to remove reclaim is so they don't have to deal with unknown randomers making their life hard.
It has nothing to do with balance.
Reclaim massively rewards aggression as it means you get to reclaim some of the mass you spent on units to win an area, therefore recouping the investment cost. Without it, then to take map control is significantly more costly than it otherwise would be, and this actually favours turtling.