Totally disagree with you on this matter. There are certain limitations to the tabs eg. the time value of each notes. To compose a melody in a person's head is not that difficult, but to write it down and make another person understand what you have written is not easy. That's why time values eg. semibreve, minim, crotchet, quaver, semiquaver are "invented" so that they are universal and can be understood by another person. The most basic thing is to have an understanding of time signatures & values, rest notes and tablature notation. Then only you're good to go.

There are free software (and paid versions) eg. TuxGuitar, PowerTab editor, Guitar Pro etc that allow us to write down tabs by just keying in the numbers to each tab lines but still requires basic knowledge about time values of each note.