Disclaimer: There are three general types of moderators, pro-tempore (temporary) moderators, elected ones and SE-employees. Elected moderators have the moderator status only for the site they were elected on, whilst SE-employees have a network-wide moderator status.
Pro-Tempore moderators are chosen when a site-proposal (on the Area51-SE-community) gets "approved". These moderators serve until the site leaves the beta-phase (and, maybe, longer, if they get elected afterwards). Thanks to Chenmunka for pointing that out.
Do they get paid by Stack Exchange?
They do not receive any money from SE. It's voluntarily, and you don't get rewarded (in a material sense, that is). I'm not too sure about that though, the mods might receive some SO swag.
The SE employees (hopefully) get paid, this is about the elected moderators.
Do they get offered jobs after months of willing service?
Some moderators had that happen IIRC, I highly doubt that that's a standard though. A few of the community managers used to be elected moderators.
Does the dedication look amazing on a resumé?
Considering that the Stack-Exchange-Network is well established by now, I'd assume it does. It (probably) won't look bad. :)
Is this a subjective question?
Partly. No-one really knows what's going on in the mind of someone else if they appeal for moderator status. Some people might try to get it simply to have more power, others might feel the "need" to repay Stack Overflow for the help it has provided them.
Are some of them employees of Stack Exchange?
Yes. There are elected moderators, and there are SE moderators.
Getting to the "actual" question:
The moderator-status comes with a few perks, one of them being access to additional privileges/tools. It also comes with drawbacks though, you have to dedicate a lot of time, and you carry a lot of responsibility.
If a regular user sees a post as spam, he flags it, which will not carry an immediate penalty for the post/author, except if it is the last flag required for deletion. If a moderator decides that a post is spam, he nukes it. Basically, your decision carries a lot more weight. A "bad" flag won't really affect you, a "bad" nuke will certainly get you some meta-attention.
I suppose not few have tried to become a moderator simply for the sake of getting access to said tools, but I think most people that volunteer for this are community members that want to help making the Stack Exchange network a better place.