Hello!
Well i wouldn't say it is necessary…or rather that it should be made a necessity. Respect is in the heart…and it depends on how one wants to show that to the person they respect.
On the other hand, it is a culture in one of the community here. And though i do not belong to it but still “touching feet” as a sign of respect really is in my heart since a long time now…i get fascinated by the fact that this is how much u respect the other person that u are touching the part of him/her that is considered the inferior most, as it touches the ground (i don't know the real logic, but yes! that's my science behind it) i have never gotten a chance to touch the feet of anyone yet..but i surely would love to, of a person for who i have the deep regard and respect for.
As for your answer, i know people who, instead of forcing this tradition upon themselves, hold great reverence in their heart and actions for the ones they respect and care about.
Hope it helped.