So it seems like tanks take a lot of money and time to produce. Does anyone find them to be a worthwhile pursuit? If so what do you do to quickly produce a lot of tanks, or is that an oxymoron?

depends on what strat it is that you are running.
sometimes they can be purchased off the public market pretty cheaply, other times you might want to buy them off of your private market and resell them.

most times it's a pain in the butt if you decide to use them.

Join SOL on the alliance server at sol.ghqnet.com and we will teach you everything. You do need some tanks to protect yourself from getting AB'd by other countries. Keep in mind you don't want to hold too much military else you will run up your expenses.

I started playing Earth in the 90's and I just started again after 8 years of not playing.

I think attacking/defending needs to be adjusted in this game. I'd like to see more in-depth strategy involved in warfare

If you are a bottomfeeder where you are raping people who don't know what they are doing then having a few tanks keeps them from suiciding easily. As long as you don't abuse anyone massively though, You should get away without need in too many tanks. ABs are a pure revenge attack--max damage for no gain.

They're worthwhile if you like to have your buildings remain intact in the event of a suicider. Tanks are also a fairly cheap way to punish someone who has landgrabbed you multiple times since in most cases, those guys spend their money on jets and turrets rather than tanks, so, you can "learn them a thing or two" by turning their country into a smoking crater.

on a number of servers people aren't allowed to ab you unless you attack them twice first (artillery barage, the tank feature of attacking), so tanks would be a waste of money in upkeep in those situations (though people with math skills should be able to determine how important that is)

cerb is dead right, though, if they do attack you more than once, and they have few to no tanks, they should get themselves a very nice learning, we've all been there before, on both sides :P

This is GT. I think he's talking about real tanks.