Tabs are like a bag of lollies. No, wait, tabs are like a bowl of rice. You couldn't live solely on bags of lollies, but you could live on bowls of rice - but a diet of rice alone is not a great diet.
But like lollies, tabs are fast, easy, instant gratification; they pep you up, make you happy and give you quick energy...but there is no real nutrition. Life doesn't have to be all about nutrition though does it? Can't we just enjoy ourselves from time to time?
The beginner guitarist is at a critical stage; I wouldn't like to put a number on it, but out of all the people who have said to me "I'd like to be able to play the guitar" and then I've shown them a few things, and push them in the right direction, lent them a guitar - so far zero have continued to pursue it. And no, I don't think it is me ;)
Playing guitar is a bit of a glamourous looking pursuit, to see a guitarist "rockin' out" looks like the most fun you could have standing up...but it represents *a lot* of practise, frustration and sweat to achieve that. So in the early days it is either immediate results - or a heck of a lot of persistence - that keeps the interest going. You need those immediate results to get past the initial hurdle.
That's where tabs come in. They are easy to learn (search wikipedia for "tablature", it's a good primer) - and tabs give you immediate results. The first thing a guitarist needs is be shown how to play the riff to "Smoke on the Water" or something really easy that they can suceed with and inspires them. Learn three chords and then be able play about a million songs. Hook them in with the easy stuff, then show them how to find tabs.
But tabs shouldn't last forever. Learning by ear, working things out by yourself, being able to sight read from music score, learning scales by rote, music theory, composing your own music - these sorts of things will round you out as a guitarist and musician.
Once you have the guitar bug for life, tabs in fact will start to feel tedious. I still refer to tabs as a reference or a starting point; however I now dislike rote learning a song from a tab. You are wondering why I generally tab out all my arrangements then aren't you? Quick answers: it's a tool for me to nut out and write down what I'm thinking during the arrangement process which often takes weeks of small increments - in fact sometimes I type stuff into powertab to see what it sounds like, before attempting to play it! - often I forget stuff if I haven't played it for a while but a quick glance at the tab gets me back on track - I like to share my stuff with the world and have people enjoy it, and then play it back to me with their own changes and twists that I never considered!
So yes, tabs are good for you, but everything in moderation - do something too much and it will stop being good for you. It's true of much in life.