I think no one is getting to the point here or may be no one wants to.
There was more than one reason to go for Apache both political and Technical.
We had to appease America by giving them some kind of deal and Apache turned out to be the most reasonable.
Besides the political need there are reasons already mentioned by users here.
Apache has a completely different role compared to LCH. In a war scenario they are most likely to operate from Punjab and Rajasthan so mostly against tank columns. Where as LCH is meant for High Altitudes like Siachen, Kashmir and Indo China border.
When tender for Heavyweight helicopter was floated LCH was still in nascent stage where it had taken its first flight. There was an urgent need of this helicopter when Pakistan was pursing viper platform.
And LCH was nowhere near full operational Capability and still isn't right now.
We will get our 22 Apache by 2021 while 55 LCH would have at least taken some 2024 to 2027. Knowing how HAL works it could've taken more.
LCH is like LCA its test bed for future platform and also a force multiplier.
With Development of Helina, indigenous engins, home grown radar and sub system LCH will become even more lethal.
And U know what, as soon as the first LCH gets inducted we will be hearing about HCH (Heavy Combat Helicopter) u know it's coming.
Apache will be the last Foreign combat helicopter I can say that for sure.
Apache is our present and LCH is both present and future.
So the comparison doesn't makes sense to me.